Exam 5: Light: the Cosmic Messenger

Studying a spectrum from a star can tell us a lot. All of the following statements are true except one. Which statement is not true?

From laboratory measurements, we know that a particular spectral line formed by hydrogen appears at a wavelength of 121.6 nanometers (nm). The spectrum of a particular star shows the same hydrogen line appearing at a wavelength of 121.8 nm. What can we conclude?

How are wavelength, frequency, and energy related for photons of light?

Which of the following is not an advantage of the Hubble Space Telescope over ground- based telescopes?

X- rays, because they have more energy, travel through space faster than visible light.

Laboratory measurements show hydrogen produces a spectral line at a wavelength of 486.1 nanometers (nm). A particular star's spectrum shows the same hydrogen line at a wavelength of 486.0 nm. What can we conclude?

When an electron in an atom goes from a higher energy state to a lower energy state, the atom

From lowest energy to highest energy, which of the following correctly orders the different categories of electromagnetic radiation?

Which of the following properties of a star can be measured directly, during a single night at the telescope?

Suppose you watch a leaf bobbing up and down as ripples pass it by in a pond. You notice that it does two full up and down bobs each second. Which statement is true of the ripples on the pond?

Most astronomical objects emit light over a broad range of wavelengths.

X- rays are more intense than radio waves.

Thermal radiation is defined as .

Why is the Earth's daytime sky blue?

The atomic nuclei of the same element always have the same number of neutrons.

Grass is green because it absorbs green light, reflecting all other colors.

Which forms of light are lower in energy and frequency than the light that our eyes can see?

Atomic number refers to ________.

Which of the following telescopes is best suited for studying the hottest intergalactic gas (10 million K)in a cluster of galaxies?

Doppler shifted hydrogen absorption lines are seen in the spectrum of a star. The hydrogen line at 656.28 nm is seen to be shifted to 656.08 nm. How large is the fractional shift in wavelength?